1. Field of the Invention
The present invention relates to a reflow soldering system which solders a printed circuit board (PCB) wherein the system features both the high heat transfer rate of heating by contact heat transfer and the uniform heating of heating by blowing hot gas.
2. Description of the Related Art
In the conventional reflow soldering method of printed circuit boards, as shown in Japanese Unexamined Patent Publication No. 2004-304098, in particular FIG. 5, the practice has been to hold a printed circuit board for heating in a preheating zone of a reflow oven at a 100 to 200° C. preheating temperature, then rapidly raise the temperature to the peak temperature. If soldering a printed circuit board by the conventional reflow soldering method, there were the problems that microballs were formed around the soldered part or the electronic devices deviated in position from the soldered parts.
In particular, to handle large numbers of types of products, it is necessary to increase the oven length for thermal soaking. The heating time was forced to become longer and the facilities to become larger in size.